1. Field of the Invention
The present invention relates to a novel class of compounds having utility as fuel additives, lubricant additives, fuel compositions, lubricant compositions and methods of making and using such additives. In particular, the present invention relates to multi-functional polyamine-containing additives effective at reducing intake valve deposits, combustion chamber deposits and octane requirement increase in gasoline engines, and methods of making and using the additive.
2. Background Discussion
Considerable effort has been expended to develop chemical products as detergents or "deposit control" additives for internal combustion engines. Oil-soluble detergent-dispersants for lubricating oil have been developed to control deposit and vanish formation, and to keep sludge and other solid matter, such as oxidized base oil, in suspension in the lubricating oil. Detergents, when added to hydrocarbon fuels employed in the engines, effectively reduce deposit formation which ordinarily occurs in carburetor ports, throttle bodies, venturies, intake ports and intake valves. The reduction of these deposit levels has resulted in increased engine efficiency and a reduction in the level of hydrocarbon and carbon monoxide emissions. However, with the advent of automobile engines that require the use of non-leaded gasolines (to prevent disablement of catalytic converters used to reduce emissions), it has been difficult to provide gasoline of high enough octane to prevent knocking and the concomitant damage which it causes. The difficulty is caused by octane requirement increase, herein called "ORI," which is due to deposits formed in the combustion chamber while the engine is operating on commercial gasoline.
Each engine, when new, requires a certain minimum octane fuel to operate satisfactorily without pinging and/or knocking. As the engine is operated on any gasoline, this minimum octane requirement increases. In most cases, if the engine is operated on the same fuel for a prolonged period it will reach equilibrium. This is apparently caused by an amount of deposits in the combustion chamber. Equilibrium is typically reached after 5000 to 15,000 miles of automobile operation.
ORI measured in particular engines with commercial gasolines will, at equilibrium, vary from 5 or 6 octane units to as high as 12 or 15 units, depending upon the gasoline compositions, engine design and type of operation. The seriousness of the problem is thus apparent. A typical current model year or older automobile with a research octane requirement of 85 when new may after a few months of operation require 97 research octane gasoline for proper operation, and little unleaded gasoline of that octane is available. The ORI problem exists in some degree with engines operated on leaded fuels. U.S. Pat. Nos. 3,144,311 and 3,146,203 disclose lead-containing fuel compositions having reduced ORI properties.
Many experts, believe the ORI problem, while present with leaded gasolines, is much more serious with unleaded fuel because of the different nature of the deposits formed with the respective fuels, the size of the increase, and because of the lesser availability of high-octane non-leaded fuels. This problem is compounded by the fact that the most common means of enhancing the octane of unleaded gasoline, increasing its aromatic content, also appears to increase the eventual octane requirement of the engine. Furthermore, some of the presently used nitrogen-containing deposit control additives with mineral oil or polymer carriers appear to contribute significantly to the ORI of engines operated on unleaded fuel.
Thus, it would be highly desirable to provide fuel compositions which contain deposit control additives which effectively control deposits in intake systems of engines, i.e., intake valve deposits (IVD), operated with fuels containing them, but do not contribute to the combustion chamber deposits (CCD) which can cause octane requirement increase (ORI).
Moreover, despite the great amount of work conducted in the field of dispersants for lubricating oils, a need exists for novel lubricating oil compositions which contain deposit control additives which effectively control deposits in lubricating systems of engines.